1. Field of the Invention
The present invention relates to a high density connector and particularly to a connector assembly utilizing such high density connectors to create a unique connection interface.
2. Description of Related Art
In card edge connectors, it is known to arrange contacts in two levels. U.S. Pat. No. 5,052,936 issued on Oct. 1, 1991 to Biechler et al. exemplifies a connector. In this design, two arrays of aligned contact members for interfacing either side of a board or card edge are insert molded to a lower subassembly housing which in turn is assembled to an upper housing. The board or card edge is provided with an upper level of contact pads and a lower level of contact pads. When the board or card edge is inserted into the housing, the lower level of contact pads electrically connect with a first array of contact members of the connector and the upper level of contact pads electrically connect with a second array of contact members.
The contact member is disposed in an unforced status when the card edge is not inserted into the housing. The contact member would tilt to contact with the contact pads of the card edge, when the card edge is inserted into the housing. When the card edge is inserted into or pulled out from the housing for many times, the contact member would become less resilient to thereby have an unreliable engagement between the card edge and the housing.
U.S. Pat. No. 6,371,773 issued on Apr. 16, 2002 to Crofoot et al. discloses a high density interconnect system used in association with printed circuit boards, circuit cards, back panels and other like substrates. The interconnect system comprises electrical connector modules each having a plurality of signal conductors substantially parallel within a first plane and a reference conductor element made of a single piece of sheet metal. The reference conductor element includes a plurality of first reference conductors substantially parallel to one another and interspersed between the signal conductors and at least part of which are in the first plane and a plurality of second reference conductors within a second plane which is offset from and substantially parallel to the first plane. The second reference conductor is aligned with the signal conductor in a direction perpendicular to the plane of the connector module. However, when the connector modules of two mating connector portions are mated, curved contact ends of mating signal conductors make a hermaphrodite mating while associated second reference conductors only shield beside the mated signal conductor but not touch each other.
The signal conductors and the reference conductors are respectively inserted on one plane to combine themselves as a whole. When it is needed to choose a certain number of conductors, it is not convenient to insert proper number of conductors into the plane, or remove the redundant conductors one by one.